Suicide Bomb Attacks in Russian City Leave Dozens Dead, Wounded

STRINGER/AFP/Getty Images(VOLGOGRAD, Russia) -- The Russian city of Volgograd was struck by separate bomb attacks over the past two days targeting its transportation system, leaving more than 30 people dead and dozens more injured, many critically.

In both cases, suicide bombers were blamed for the powerful blasts, but there was no claim of responsibility for either.

Monday’s explosion occurred on a trolley bus during the morning rush hour, leaving at least 14 people dead and two dozen injured.

Meanwhile, at least 17 people died Sunday morning when Russian authorities said a female suicide bomber blew herself up at a Volgograd railway station. As many as three dozen others were also wounded in the blast.

Last October, Volgograd was also the scene of a bus explosion that killed six, including a woman linked to an explosives expert working with an Islamic group.

In Washington Sunday, the White House issued a statement that said, "Our hearts go out to the victims and their families." NATO also condemned the attack in Volgograd, once known as Stalingrad.

The bombing is particularly problematic for Russia as it prepares to host the Winter Olympics in Sochi in less than six weeks. Volgograd is located about 400 miles from the Olympic site, which sits on the Black Sea coast.

According to the Investigative Committee of Russia, the bomber during Sunday’s explosion used the equivalent of 22 pounds of TNT, which also included shrapnel in order to maximize casualties.